String manipulATion and pATtern mATching language by Klint & Sint ATCWI in the lATe 1970s. It was recently used as the input and implementATion language for the {DATaflow Compiler Project} AT {CWI}. ["An Overview of the SUMMER Programming Language", Paul Klint, 7th POPL, ACM 1980, pp. 47-55].